Update README.md

[pvcresin]

Updated documentation as many people are confused by gulp v5

• ref: Not working with Gulp 5 #205 (comment)

Proposed changes

• Add docs for gulp v5 case
  • (I'm also putting out a PR for changes to the gulp documentation.)
    • Update dest.md (add description for encoding option) gulpjs/gulp#2828

Code quality

• I made some tests for my changes
• I added my name in the
  contributors
  field of the package.json file. Beware to use the same format than for the author field
  for the entries so that you'll get a mention in the README.md with a link to your website.

License

To get your contribution merged, you must check the following.

• I read the project license in the LICENSE file
• I agree with publishing under this project license

Join

• I wish to join the core team
• I agree that with great powers comes responsibilities
• I'm a nice person

My NPM username: